Fluid fuel burner



March 10, 1936. E. J, LATTNER FLUID FUEL BURNER Filed Nov. 12, 1932 2 Sheets-Sheet 1 INVENTOR. 575/27 Kerr/v52,

A TTORNEY.

March 10, 1936. J LATTNER 2,033,837

I FLUID FUEL BURNER Filed Nov. 12, 1932 2 sneets sneet 2 J'Ti ii I M i II i .7 INVENTOR.

237567 [Zarwvzx Patented Mar. 10, 1936 UNITED STATES PATENT OFFICE FLUID FUEL BURNER Emert .I. Lattner, Cedar Rapids, Iowa Application November 12, 1932, Serial No. 642,441

1 Claim. (Cl. 158-76) This invention relates to fluid fuel burners and particularly to that type of burner using such liquid fuel as distillate, fuel oil, kerosene, or the like and in which the oil is atomized and mixed with a blast, of air delivered into the furnace by suitable air circulating means.

In oil burners of the type referred to, the fuel and air are mixed by atomizing the liquid fuel under pressure from a nozzle usually enclosed within a tube or'conduit through which air at a fairly high velocity is delivered. Means are provided for igniting the mixture, and such means are usually the form of ignition points across which an electrical spark is caused to jump continuously by means of a high potential transformer or other source of high potential current. The burners are usually mounted by means of a suitable base upon the floor or any other suitable foundation in front of the furnace with the blast conduit projecting into the furnace.

I have observed that with the devices of the prior art the flame resulting from the burning of the mixture of atomized fuel and air is uneven; that is, that portions of the flame will burn with a color indicating an over-rich mixture while other portions of the flame will burn with a color indicating a lean or thin mixture.

These ineflicient combustion conditions result in loss in efliciency of the burner as a heating means and often result in smoking and sooting of the heater. These conditions are probably caused by unequal flow of the air issuing from the blast conduit.

I have observed also that the devices of the prior art are oftentimes troublesome by reason of undesirable noise produced by the burner while in operation. A portion of this noise is probably due to the rapid flame propagation and is augmented by any pulsations in the delivery of the fuel and air. This flame noise, whatever its cause, is partially muflled within the furnace, but escapes, in many cases, through the air conduit and the air inlet to the blower. Whether this noise is conducted through the air screen or the material of the blast tube, or both, is not well known.

Another source of noise from the burner is that arising from the motor. Any vibration of the motor, in the devices of the prior art, is

transmitted through the frame of the burner to thebase and from thence to the flooror foundation which acts as a sounding board to amplify the noise caused by vibration of the motor and blower parts.

Another source of 'diiliculty in the devices of the prior art has been the transformer and transformer leads which furnish high potential current to the ignition points. The transformer terminals were located on the outside of the transformer box or housing and the leads passed 5 through the wall of the blast tube to the ignition points. The transformer terminals became dirty and, by reason of moisture in the air in the basement or other room in which the burner was located, breakdown at the terminals or at m the point where the leads passed through the blast tube occurred. The exposed terminals afforded a means whereby a person might be severely shocked and the terminals constituted unsightly projections on the transformer housing.

I have devised means for overcoming the dimculties above pointed out and it is a general object of my invention to provide a new and improved oil burner and oil burner control means.

A more specific object of my invention is to provide means for increasing the effectiveness and economy of operation, to improve the flame distribution and color, and very materially reduce the noises resulting from the operation of such burners.

Another object of my invention is to provide means for minimizing the efiects of vibration in the burner.

Another object of my invention is to provide an improved ignition system for oil burners of the above description.

Other and further features and objects of the invention will be more apparent to those skilled in the art upon a consideration of the accompanying drawings and following specification, wherein is disclosed several exemplary embodiments of the invention, with the understanding, however, that such changes may be made therein as fall within the scope of the appended claims without departing from the spirit of the inven- 40 tion. The devices may be used or adapted for use for other purposes.

In the drawings:

Figure 1 is a top plan view partly in section of a burner constructed according to one embodiment of my invention. Portions of the structure have been broken away to show the remaining parts in greater detail.

Figure 2 is an elevational view, taken from the left side, of the device shown in Figure 1. In this view also, portions of the structure have been broken away in order to show the remaining parts in greater detail.

Figure 3 is an elevational view, taken from the right side, of the device shown in Figures 1 and 2, and

Figures 4, 5, and 6 are views in perspective in exploded relation of the means for supporting the main portion of the burner on a base.

Referring now to the drawings, the burner structure as a whole is mounted upon a base III which may be secured to the floor or other suitable foundation by means of bolts II. A standard I 2 projects vertically from the base l0 and affords a means whereby the fan housing I3, which acts also as a main frame member, may be mounted upon the base.

The box-like housing I3 is provided with a U-shaped bracket member M at the rear wall thereof, and a cylindrical resilient member I5, preferably of rubber or the like, is disposed on the standard I2 at a distance from the base of the standard such that when the bracket I4 is clamped on the member l5 of the standard l2 by means of the clamp I5 and bolts H, the burner will be properly spaced from the floor.

The resilient member l5 affords a resilient connection between the burner and the standard such that the vibration of the motor, the fan, and fuel pump hereinafter described, is absorbed and is not transmitted through the base to the floor. In this way unpleasant vibration and noise emanating from the burner is greatly minimized. This feature is of considerable importance because any noise or vibration arising from the oil burner may be very annoying and may even result in dissatisfaction with the burner installation by the owner.

A driving motor N3 of any usual construction, is bolted to the left side of the housing l3 by means of bolts H). The shaft of the motor projects into the housing l3 and a fan 20 for driving air into and through the blast conduit 26, is mounted on the end of the shaft. The rotating parts of the fuel pump 43 are also driven by the shaft of the motor l8. In the present instance, any suitable fan and fuel pump may be employed and therefore these parts will not be further described.

It,is very desirable that the axis of the fan be located below the center-line of the blast conduit 26 in order to lower the center of gravity of the mass of the burner, and in order that the fuel control devices mounted on the right hand side of the housing l3 will be located below the nozzle 25 and nozzle feed pipe 21.

The right side of the housing I3 is closed by means of an end bell 33 having radially slotted openings 34 to permit air to pass through the end bell and into the housing l3. The end bell is provided with a flanged outer end 36 to afford a mounting for the pump 43.

A filter 48 and fuel flow control valve 51 are mounted respectively on the rear and front of the fuel pump 63 and fuel entering the filter 48 from the fuel supply line 41 passes through the filter and into the pump 43., The fuel is pumped from the pump 43 into the control valve 51. The fuel which is eventually burned is conducted from the valve 51 to the supply pipe 21 by means of elbows 68, pipe connections 69, pipe ll, elbow 12, pipe 73, and elbow 14. It is to be noted again at this point that fuel is pumped upwardly from the valve 51 to the pipe 21.

The blast conduit 26 is preferably an integral part of the housing l3 and extends forwardly therefrom in a series of convolutions indicated at 16 for a space substantially the same as the length of the housing l3. The extreme forward portion of the blast conduit 26 is formed into a cylindrical member 1'! partially closed at its outer end by means of a circular flange 18. A large opening 19 is provided in the outer end of the blast conduit to permit air from the fan and fuel from the burner nozzle 25 to issue from the blast conduit. The construction of the nozzle 25 is such as to cause the fuel to be atomized and subsequently, by reason of the blast of air from the conduit, this atomized fuel is thoroughly mixed with the air, to issue from the blast conduit as a vapor. The flange I8 assists in mixing the air with the fuel.

It is to be noted that the diameter of the blast conduit at successive convolutions 16 decreases in diameter in inverse proportion to the spacing from the housing I 3. The purpose of the convolutions or corrugations I6 is to equalize the air pressure and velocity of the air throughout the cross section of the conduit. It is probable that the eddies created by these convolutions or corrugations are responsible for the equalization of the velocity and pressure throughout the tube. Furthermore these eddies, when carried along the tuba-aid in the mixing of the oil and air. The corrugations also seem to greatly restrict the effects of sound and vibration set up by reason of the flow of air and fuel and the noise and vibration due to burning of the fuel. It has also been found that by reducing the diameter of the corrugated portion of the blast conduit in proportion to the spacing from the housing l3, any noise or vibration is also very much minimized.

Without attempting to explain further the operation of this corrugated section of the blast tube or conduit, it may be stated that practice has proven that it not only reduces the noise of the air passing through the blast tube, but it effectively prevents the return of the flame noises through the tube and their emission from the air inlets 34. When the burner is operated without such a corrugated section, there is a decided noise of the flame at the inlet which is substantially entirely eliminated by the use of the presen invention.

It will, of course, be understood that the form of that portion of the blast tube which is effective in improving the operation of the burner, is subject to considerable variation and need not be corrugated but can be provided, for instance, with inwardly projecting fins, ribs, or the like, or any other configurations, circular or helical, the functions of which are to retard and eddy the air passing thereover to permit it to equalize in pressure and velocity before passing through the blast conduit. In fact, it has been found that merely reducing the diameter of a simple cylinder in proportion to the distance from the housing I3 is effective to minimize the noises before mentioned.

In the present instance, I prefer to make the top half of the corrugated portion 28 of the blast conduit removable in order to provide ready access to the inside of the conduit for cleaning thereof and for cleaning and adjusting the parts of the burner located inside the blast conduit.

The fuel vapor issuing from the end of the blast conduit 26 must be ignited by any suitable pilot flame or other flame source. In the present instance, I preferably employ a high frequency spark for igniting this vapor. Two electrodes 8| and 82 are disposed with their outer ends turned towards each other to a position above and slightly in front of the nozzle 25. The electrodes are supported by a bracket 83 which also serves a, support for the nozzle fuel feed pipe 21. The bracket preferably rests on the inner rear portion of the cylindrical part 11 of the blast conduit. A source of high tension cur- I rent must be supplied and I preferably employ a transformer 84 which may be of any suitable construction. The transformer is preferably located on the upper face of the frame housing l3 and electrical energy for energizing the transformer is conducted from the switch box 86, which controls the motor l8, to the transforme by means of an electrical connector 81.

,It is the usual practice for the terminals of the transformer to be located on the side of the transformer case 84 and for the leads to pass through suitable insulators in the wall of the blast conduit and to the electrodes 8| and 82. The exposed terminals are a source of trouble and danger in that they are likely to become dirty and to cause short circuits. It is quite possible that a person accidentally touching the burner while it is in operation may be badly shocked by these exposed electrodes. The junction point where the leads enter into the blast conduit is also a source of difficulty in that short circuits and the like are likely to occur at this point also. In addition, the electrical protection necessary in the form of extra insulation is expensive. I have accordingly devised a means whereby the high tension connections are all enclosed within the blast conduit.

In a preferred construction I provide an opening 88 in the front portion of the upper wall of the frame housing l3, and arrange the terminals 88 of the transformer 84 so that they project from the bottom thereof. When the transformer is located on top. of the frame member I3 the terminals 89 project through the opening 88 and into the interior of the housing I3. The conductors 8|, which are connected to the electrodes ill and 82, pass directly back through the corrugated portion of the blast conduit to the terminals 88, where they are electrically connected with the transformer.

It is apparent with this construction that the high tension electrical leads are entirely enclosed within the blast conduit from the point where they issue from the transformer up to and including the electrodes themselves and that by this construction the possibility of short circuiting or other breakdown of the insulation between the two electrodes is minimized. Furthermore the necessity of insulation of the leads as they pass through the walls of the blast conduit is eliminated, thus making a less expensive structure.

Although this invention has been described in connection with certain specific embodiments, the principles involved are susceptible of numerous other applications that will readily occur to 7 persons skilled in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended claim.

I claim as my invention:

In an oil burner, a fan housing, a blast conduit projecting forwardly from the fan housing, a fuel burner nozzle within the remote end of the blast conduit, a motor secured to and entirely supported from one side of the housing, a fan within the housing driven by the shaft of the motor, a fuel pump secured to and entirely supported from the side of the housing remote from the motor, a fuel flow control means secured to one side of the fuel pump and. supported thereby, the axes of the motor, the fan, fuel pump and fuel flow control means all being located below the horizontal plane in which the nozzle is located, and a fuel supply pipe leading from the fuel flow control means-through the wall of the blast conduit adjacent the housing and extending forwardly within the blast conduit to the nozzle, all port'ions of said pipe between the fuel flow control means and the point where the pipe passes through the wall of the blast conduit being located below a horizontal plane which is in line with the nozzle.

EMERT J. LATINER. 

